1. Field of Invention
The invention relates to an apparatus for positioning a bowling ball during a drilling process and in particular to an apparatus and method that provides reproducible orientations of the ball for accurately modifying and repeating the drilling process.
2. Background Art
Bowling ball construction has become hi-tech over the last several years. Inner core designs generate varied amounts of hitting power, tailored tracking on a lane, and higher revolutions. Such ball improvements have placed increased demand on properly fitting a bowling ball to a bowler. Most bowlers must pay a cost of losing several pins dropped or frames lost every time they switch balls and acclimate themselves to a different feel. This difference in feel make the bowler reluctant to change balls even when a change is needed.
It is generally recognized by experienced bowlers that finger holes in a bowling ball play a critical role in providing the bowler with a proper feel for holding and releasing the bowling ball in a consistent manner. The control that a bowler has over a bowling ball is dependent on the placement, orientation, and cross-sectional configuration of the holes in the ball. As is generally the case in sports, a basic form is sought and typically found but it is the process of repeating and continuing to repeat this form under the multitude of conditions presented during competition, not least of which is achieving a feel that provides the confidence to score well. The fit of the ball is always under consideration.
It is also well known and accepted in the art of bowling ball drilling, that obtaining the basic measurements takes an experienced ball driller and if such measurements were to be drilled by different experienced drillers, the fit would be only similar. Variances and errors in bevel size, drilling spans and pitches would vary. Technique varies even with experienced drillers and typically it is a trial and error method that ultimately provides the bowler with a desired fit.
U.S. Pat. No. 3,263,531 discloses a bowling ball drill jig for drilling thumb and finger holes comprising a moveable apparatus for locating the center point of the hole to be drilled and selecting a desired plane for the axis of the hole to be drilled. Calibration means is employed to account for hole edges. The patent teaches the importance of being able to fix and hold the ball in a jig for greater drilling accuracy without having to move or remove the ball from the jig after each hole is drilled to allow proper measurement for drilling succeeding holes.
U.S. Pat. No. 3,521,506 discloses a method and apparatus for forming oblong holes of predetermined orientation in a bowling ball by superimposing a target with radial lines at predetermined angles, all radiating from a common center on a selected point on a line on the ball. The line is rotated on the ball into coincidence with one of the radial lines, making a round hole in the ball. The ball is then moved a predetermined distance along one of the radial lines and additional material is removed from the side wall of the hole opposite the direction of motion to make the hole oblong.
U.S. Pat. No. 3,095,767 discloses an apparatus and method for drilling holes in a bowling ball and reproducing the holes of a first bowling ball into a second bowling ball by positioning the first bowling ball into a cradle, positioning inserts in each finger hole and providing a guide rod for establishing a locking position for tool holders. The guide rod is removed; the second bowling ball is placed in position of the first; and holes drilled based on the guided selections.
In a manual for bowling pro shops and knowledgeable bowlers, "Fitting and Drilling a Bowling Ball" by Bill Taylor, the author points out the problems in properly fitting a bowler for drilling a bowling ball and even though it may be known what measurements are needed, accurately obtaining the measurements is not so simple. The author further points out that too many ill fitted balls result from inexperienced ball drillers. Twelve measurements are discussed for providing a proper fit which permits a proper swing and a proper release to maximize a bowler's chances for a satisfactory delivery. The author discloses methods for measuring a bowlers hand and fingers for obtaining a set of measurements that can satisfy the bowler's needs. However, the author points out that though there are many talented ball drillers, most of them become talented by trial and error and in doing so cause many problems in the course of their self education.